1. Field of the Invention
This invention relates to bicycle locks, specifically to such locks which are mounted to a bicycle frame and provide a means to extend through the spokes of a wheel thus preventing its rotation.
2. Description of Prior Art
In an effort to promote ease of use and convenience in a bicycle lock, several inventions have been generated for devices which are permanently, or semi-permanently attached to the bicycle frame. These devices generally include a pivotally mounted member which swings between the spokes of a wheel thereby preventing rotation of the wheel in the locked position.
While most of these inventions offer convenience and ease of use, the actual security they provide is marginal. The majority of these devices are inadequate for the following two reasons:
(a) The threaded fasteners which secure the locks to the bicycle frame are often exposed in the locked position and are prone to easy removal.
(b) The devices utilize bicycle frame attachment hardware that is structurally deficient and vulnerable to prying and forced debilitation or removal.
From a review of these inventions, it seems that much of the design effort has gone into the actual locking mechanisms while the bicycle frame mounting methods have been neglected. U.S. Pat. No. 2,691,289 to Wollaston (1950) shows a rod pivotally mounted to the bicycle frame adjacent to the rear wheel. The device description clearly indicates that the mounting fasteners are exposed in the locked position. It is evident that the locking device itself could easily be removed with an allen wrench or similar tool. Wollaston states that a specially sized allen wrench could be utilized to attach the lock. This solution is not ideal, as the tool would have to be supplied with the lock and retained in order to make mounting adjustments or transfer the lock to another bicycle. In addition, since the mounting screws are exposed, a would-be thief might easily find a suitably sized object to remove them and thus the lock.
Wollaston's device also appears vulnerable to prying and forced debilitation. The intricate locking mechanism is encased in a small housing and would not withstand a significant torque or shear force. A moderate force applied at the free end of the pivotally mounted locking bar would be sufficient to bend or shear off the anti-rotation pins of the locking mechanism.
U.S. Pat. No. 2,604,774 to McFall (1949) discloses a solution to this problem. A clamp with a socket is attached to a bicycle frame member on the opposite side of the wheel from the locking mechanism. The pivotally and slidably mounted locking bar has a tongue which extends through this socket in the locked position. This arrangement would prevent the application of a significant torque to the locking bar by securing its free end. McFall realized that a debilitating torque could readily be applied to the locking bar and devised this solution. However, the nuts which secure the socketed clamp to the bicycle frame are easily accessible and readily removed. Once this has been accomplished, the lock may be quickly rendered ineffective.
The problem of accessible and thus removable mounting fasteners is addressed by the device described in U.S. Pat. No. 2,480,481 to Kelly (1946). In this design the screw heads are encased in the lock housing preventing their removal. However, the mounting clamp is oriented in such a way as to facilitate rotation of the entire mechanism about the bicycle frame member to which it is attached. The frictional force of the clamp could easily be overcome and the lock rotated thus moving the slidable locking bar out from between the spokes.
Another disadvantage of Kelly's device is the potential safety hazard produced by the slidable locking bar. In the riding or unlocked position, the bar protrudes a significant distance from the bicycle frame in a perpendicular direction. The protruding bar could easily become entangled or strike a stationary object as the rider passed by, resulting in an accident. In addition, the protruding bar poses a severe injury risk to a rider in the event of any accident.
All of the permanently attached, spoke traversing bicycle locks heretofore known lack a significant amount of security. All are vulnerable to prying, torquing, and other types of forced debilitation. They are also susceptible to relatively easy removal due to weak or exposed bicycle frame mounting arrangements. In addition, most of these devices and all three mentioned previously suffer from the following disadvantages:
(a) Their manufacture requires the assembly of a relatively large number of components into confined housings. This increases costs due to the necessary tight machining tolerances and assembly time. In addition, the devices are not rugged due to the down-sizing of components required for space minimization.
(b) The devices are mounted in close proximity to the spokes of the bicycle wheel. The potential of the lock mountings to become loose during vehicle operation is very high due to the vibrational environment. If one of these devices became entangled in the spokes while riding, a serious accident and/or injury could occur.
(c) The large number of moving parts and close assembly fits contained in these locks pose a reliability problem. The operational environment including intrusion of dirt and exposure to the elements could easily jam one of these mechanisms rendering the device inoperative.
Accordingly, several objects and advantages of my invention are:
(a) to provide an anti-theft device which may be permanently attached to a bicycle frame and in conjunction with a standard padlock, creates a high security spoke traversing bicycle lock; this invention offers added convenience by eliminating the need to carry and manipulate a cumbersome peripheral bicycle lock;
(b) to provide a bicycle anti-theft device which is easily mounted on a bicycle frame using a single standard tool;
(c) to provide a bicycle anti-theft device with a mounting arrangement that absolutely prevents access to the mounting fasteners in the locked position thereby preventing removal by an unauthorized individual;
(d) to provide a bicycle anti-theft device which is of rugged construction impervious to prying and all types of forced debilitation;
(e) to provide a bicycle anti-theft device which is of simple design with minimal moving parts thus reducing cost and increasing reliability; and
(f) to provide a bicycle anti-theft device which is mounted in such a way as to prevent all possibility of spoke interference during vehicle operation.
Further objects and advantages of my invention are to provide a bicycle anti-theft device which completely encompasses the adjacent wheel section when locked (a security advantage that the majority of prior spoke traversing locks lack), which is simple to use and inexpensive to manufacture, which is easily adjustable and transferrable to any number of bicycles if desired, and which is compatible with a wide variety of bicycles. Still further objects and advantages will become apparent from a consideration of the ensuing description and drawings.